Skid loaders are typically four-wheel vehicles with the wheels mechanically locked in synchronization on each side, and the left-side drive wheels can be driven independently of the right-side drive wheels. The wheels typically have no separate steering mechanism and hold a fixed straight alignment on the body of the machine. By turning the left and right wheel pairs at different speeds, the machine turns by skidding, or dragging its fixed-orientation wheels across the ground. The extremely rigid frame and strong wheel bearings prevent the torsional forces caused by this dragging motion from damaging the machine. The skid-steering vehicle is turned by generating differential velocity at the opposite sides of the vehicle.
The conventional bucket of some skid loaders can be replaced with a variety of specialized buckets or attachments that can be powered or controlled at least in part by the loader's hydraulic system.